build: update opam-repo version to use the latest jsoo.3.11.0

Use the latest version of js_of_ocaml. This is a requirement for a future MR to import the latest alcotest and have it work in javascript. Corresponding opam-repo MR opam-repository!203 (closed)

Context

Manually testing the MR

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, the Development Version section of CHANGES.md for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR